Halos

"All you have to do is to touch your eyes with the magic
wand called: I have to know where I have to heed to”

(Marcel Minnaert)

Halos are arcs and spots of light in the sky caused
by refraction and reflection of light from ice crystals. Ice crystals
generating halos mainly exist in high clouds (cirrus and cirrostratus).
But halos can also be observed in falling snow crystals, freezing fog,
on snow covers and on surfaces covered with hoar-frost.

Contrary to rainbows,
these atmospheric phenomena are hardly common to anyone. But there are
some types of halos which can be as colourful and bright as a rainbow.
And halos are not very rare. In average it is possible to observe halos
on 6 to 7 days a month. The following pages are designed to get you in
touch with the variability of the different types of halos and to encourage
you to observe these fascinating sights in the sky yourself.